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-rw-r--r--doc/manual/installation/installing-binary.xml301
1 files changed, 290 insertions, 11 deletions
diff --git a/doc/manual/installation/installing-binary.xml b/doc/manual/installation/installing-binary.xml
index 3f57f47b5..8d548f0ea 100644
--- a/doc/manual/installation/installing-binary.xml
+++ b/doc/manual/installation/installing-binary.xml
@@ -6,16 +6,30 @@
<title>Installing a Binary Distribution</title>
-<para>If you are using Linux or macOS, the easiest way to install Nix
-is to run the following command:
+<para>
+ If you are using Linux or macOS versions up to 10.14 (Mojave), the
+ easiest way to install Nix is to run the following command:
+</para>
<screen>
$ sh &lt;(curl https://nixos.org/nix/install)
</screen>
-As of Nix 2.1.0, the Nix installer will always default to creating a
-single-user installation, however opting in to the multi-user
-installation is highly recommended.
+<para>
+ If you're using macOS 10.15 (Catalina) or newer, consult
+ <link linkend="sect-macos-installation">the macOS installation instructions</link>
+ before installing.
+</para>
+
+<para>
+ As of Nix 2.1.0, the Nix installer will always default to creating a
+ single-user installation, however opting in to the multi-user
+ installation is highly recommended.
+ <!-- TODO: this explains *neither* why the default version is
+ single-user, nor why we'd recommend multi-user over the default.
+ True prospective users don't have much basis for evaluating this.
+ What's it to me? Who should pick which? Why? What if I pick wrong?
+ -->
</para>
<section xml:id="sect-single-user-installation">
@@ -36,7 +50,7 @@ run this under your usual user account, <emphasis>not</emphasis> as
root. The script will invoke <command>sudo</command> to create
<filename>/nix</filename> if it doesn’t already exist. If you don’t
have <command>sudo</command>, you should manually create
-<command>/nix</command> first as root, e.g.:
+<filename>/nix</filename> first as root, e.g.:
<screen>
$ mkdir /nix
@@ -47,7 +61,7 @@ The install script will modify the first writable file from amongst
<filename>.bash_profile</filename>, <filename>.bash_login</filename>
and <filename>.profile</filename> to source
<filename>~/.nix-profile/etc/profile.d/nix.sh</filename>. You can set
-the <command>NIX_INSTALLER_NO_MODIFY_PROFILE</command> environment
+the <envar>NIX_INSTALLER_NO_MODIFY_PROFILE</envar> environment
variable before executing the install script to disable this
behaviour.
</para>
@@ -81,12 +95,10 @@ $ rm -rf /nix
<para>
You can instruct the installer to perform a multi-user
installation on your system:
-
- <screen>
- sh &lt;(curl https://nixos.org/nix/install) --daemon
-</screen>
</para>
+ <screen>sh &lt;(curl https://nixos.org/nix/install) --daemon</screen>
+
<para>
The multi-user installation of Nix will create build users between
the user IDs 30001 and 30032, and a group with the group ID 30000.
@@ -136,6 +148,273 @@ sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist
</section>
+<section xml:id="sect-macos-installation">
+ <title>macOS Installation</title>
+
+ <para>
+ Starting with macOS 10.15 (Catalina), the root filesystem is read-only.
+ This means <filename>/nix</filename> can no longer live on your system
+ volume, and that you'll need a workaround to install Nix.
+ </para>
+
+ <para>
+ The recommended approach, which creates an unencrypted APFS volume
+ for your Nix store and a "synthetic" empty directory to mount it
+ over at <filename>/nix</filename>, is least likely to impair Nix
+ or your system.
+ </para>
+
+ <note><para>
+ With all separate-volume approaches, it's possible something on
+ your system (particularly daemons/services and restored apps) may
+ need access to your Nix store before the volume is mounted. Adding
+ additional encryption makes this more likely.
+ </para></note>
+
+ <para>
+ If you're using a recent Mac with a
+ <link xlink:href="https://www.apple.com/euro/mac/shared/docs/Apple_T2_Security_Chip_Overview.pdf">T2 chip</link>,
+ your drive will still be encrypted at rest (in which case "unencrypted"
+ is a bit of a misnomer). To use this approach, just install Nix with:
+ </para>
+
+ <screen>$ sh &lt;(curl https://nixos.org/nix/install) --darwin-use-unencrypted-nix-store-volume</screen>
+
+ <para>
+ If you don't like the sound of this, you'll want to weigh the
+ other approaches and tradeoffs detailed in this section.
+ </para>
+
+ <note>
+ <title>Eventual solutions?</title>
+ <para>
+ All of the known workarounds have drawbacks, but we hope
+ better solutions will be available in the future. Some that
+ we have our eye on are:
+ </para>
+ <orderedlist>
+ <listitem>
+ <para>
+ A true firmlink would enable the Nix store to live on the
+ primary data volume without the build problems caused by
+ the symlink approach. End users cannot currently
+ create true firmlinks.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ If the Nix store volume shared FileVault encryption
+ with the primary data volume (probably by using the same
+ volume group and role), FileVault encryption could be
+ easily supported by the installer without requiring
+ manual setup by each user.
+ </para>
+ </listitem>
+ </orderedlist>
+ </note>
+
+ <section xml:id="sect-macos-installation-change-store-prefix">
+ <title>Change the Nix store path prefix</title>
+ <para>
+ Changing the default prefix for the Nix store is a simple
+ approach which enables you to leave it on your root volume,
+ where it can take full advantage of FileVault encryption if
+ enabled. Unfortunately, this approach also opts your device out
+ of some benefits that are enabled by using the same prefix
+ across systems:
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ Your system won't be able to take advantage of the binary
+ cache (unless someone is able to stand up and support
+ duplicate caching infrastructure), which means you'll
+ spend more time waiting for builds.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ It's harder to build and deploy packages to Linux systems.
+ </para>
+ </listitem>
+ <!-- TODO: may be more here -->
+ </itemizedlist>
+
+ <!-- TODO: Yes, but how?! -->
+
+ It would also possible (and often requested) to just apply this
+ change ecosystem-wide, but it's an intrusive process that has
+ side effects we want to avoid for now.
+ <!-- magnificent hand-wavy gesture -->
+ </para>
+ <para>
+ </para>
+ </section>
+
+ <section xml:id="sect-macos-installation-encrypted-volume">
+ <title>Use a separate encrypted volume</title>
+ <para>
+ If you like, you can also add encryption to the recommended
+ approach taken by the installer. You can do this by pre-creating
+ an encrypted volume before you run the installer--or you can
+ run the installer and encrypt the volume it creates later.
+ <!-- TODO: see later note about whether this needs both add-encryption and from-scratch directions -->
+ </para>
+ <para>
+ In either case, adding encryption to a second volume isn't quite
+ as simple as enabling FileVault for your boot volume. Before you
+ dive in, there are a few things to weigh:
+ </para>
+ <orderedlist>
+ <listitem>
+ <para>
+ The additional volume won't be encrypted with your existing
+ FileVault key, so you'll need another mechanism to decrypt
+ the volume.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ You can store the password in Keychain to automatically
+ decrypt the volume on boot--but it'll have to wait on Keychain
+ and may not mount before your GUI apps restore. If any of
+ your launchd agents or apps depend on Nix-installed software
+ (for example, if you use a Nix-installed login shell), the
+ restore may fail or break.
+ </para>
+ <para>
+ On a case-by-case basis, you may be able to work around this
+ problem by using <command>wait4path</command> to block
+ execution until your executable is available.
+ </para>
+ <para>
+ It's also possible to decrypt and mount the volume earlier
+ with a login hook--but this mechanism appears to be
+ deprecated and its future is unclear.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ You can hard-code the password in the clear, so that your
+ store volume can be decrypted before Keychain is available.
+ </para>
+ </listitem>
+ </orderedlist>
+ <para>
+ If you are comfortable navigating these tradeoffs, you can encrypt the volume with
+ something along the lines of:
+ <!-- TODO:
+ I don't know if this also needs from-scratch instructions?
+ can we just recommend use-the-installer-and-then-encrypt?
+ -->
+ </para>
+ <!--
+ TODO: it looks like this option can be encryptVolume|encrypt|enableFileVault
+
+ It may be more clear to use encryptVolume, here? FileVault seems
+ heavily associated with the boot-volume behavior; I worry
+ a little that it can mislead here, especially as it gets
+ copied around minus doc context...?
+ -->
+ <screen>alice$ diskutil apfs enableFileVault /nix -user disk</screen>
+
+ <!-- TODO: and then go into detail on the mount/decrypt approaches? -->
+ </section>
+
+ <section xml:id="sect-macos-installation-symlink">
+ <!--
+ Maybe a good razor is: if we'd hate having to support someone who
+ installed Nix this way, it shouldn't even be detailed?
+ -->
+ <title>Symlink the Nix store to a custom location</title>
+ <para>
+ Another simple approach is using <filename>/etc/synthetic.conf</filename>
+ to symlink the Nix store to the data volume. This option also
+ enables your store to share any configured FileVault encryption.
+ Unfortunately, builds that resolve the symlink may leak the
+ canonical path or even fail.
+ </para>
+ <para>
+ Because of these downsides, we can't recommend this approach.
+ </para>
+ <!-- Leaving out instructions for this one. -->
+ </section>
+
+ <section xml:id="sect-macos-installation-recommended-notes">
+ <title>Notes on the recommended approach</title>
+ <para>
+ This section goes into a little more detail on the recommended
+ approach. You don't need to understand it to run the installer,
+ but it can serve as a helpful reference if you run into trouble.
+ </para>
+ <orderedlist>
+ <listitem>
+ <para>
+ In order to compose user-writable locations into the new
+ read-only system root, Apple introduced a new concept called
+ <literal>firmlinks</literal>, which it describes as a
+ "bi-directional wormhole" between two filesystems. You can
+ see the current firmlinks in <filename>/usr/share/firmlinks</filename>.
+ Unfortunately, firmlinks aren't (currently?) user-configurable.
+ </para>
+
+ <para>
+ For special cases like NFS mount points or package manager roots,
+ <link xlink:href="https://developer.apple.com/library/archive/documentation/System/Conceptual/ManPages_iPhoneOS/man5/synthetic.conf.5.html">synthetic.conf(5)</link>
+ supports limited user-controlled file-creation (of symlinks,
+ and synthetic empty directories) at <filename>/</filename>.
+ To create a synthetic empty directory for mounting at <filename>/nix</filename>,
+ add the following line to <filename>/etc/synthetic.conf</filename>
+ (create it if necessary):
+ </para>
+
+ <screen>nix</screen>
+ </listitem>
+
+ <listitem>
+ <para>
+ This configuration is applied at boot time, but you can use
+ <command>apfs.util</command> to trigger creation (not deletion)
+ of new entries without a reboot:
+ </para>
+
+ <screen>alice$ /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B</screen>
+ </listitem>
+
+ <listitem>
+ <para>
+ Create the new APFS volume with diskutil:
+ </para>
+
+ <screen>alice$ sudo diskutil apfs addVolume diskX APFS 'Nix Store' -mountpoint /nix</screen>
+ </listitem>
+
+ <listitem>
+ <para>
+ Using <command>vifs</command>, add the new mount to
+ <filename>/etc/fstab</filename>. If it doesn't already have
+ other entries, it should look something like:
+ </para>
+
+<screen>
+#
+# Warning - this file should only be modified with vifs(8)
+#
+# Failure to do so is unsupported and may be destructive.
+#
+LABEL=Nix\040Store /nix apfs rw,nobrowse
+</screen>
+
+ <para>
+ The nobrowse setting will keep Spotlight from indexing this
+ volume, and keep it from showing up on your desktop.
+ </para>
+ </listitem>
+ </orderedlist>
+ </section>
+
+</section>
+
<section xml:id="sect-nix-install-pinned-version-url">
<title>Installing a pinned Nix version from a URL</title>